FOR the past few years, we've had it drummed into us by health promotion experts that to prevent cancer, it's best to eat four or five servings a day of fresh fruit and vegetables. Parents try to sneak fruit and vegetables into their kids at every opportunity.
But the reality is that many of the fruit and vegetables we consume are contaminated with pesticide residues. The apple we eat to keep us well could actually trigger a tumour. And no one is at greater risk than children.
The "Maximum Residue Limits" (MRLs) which supposedly keep pesticide limits down to safe levels are based on the average adult diet and on the tolerance of the average adult body, not on children's bodies. In Our Children's Toxic Legacy: How Science and Law Fail to Protect is from Pesticides (Yale University Press) Yale University lecturer John Wargo, one of the world's foremost experts on pesticides and children, argues that science is failing to protect them by refusing to investigate children's special vulnerability to pesticides.
This puts into perspective the recent reassuring revelations by the Department of Agriculture that in 1994, out of 1,171 samples of fruit and vegetables, only three samples were above the MRL and that in 1995, out of 1,055 samples taken only 10 were above the MRL. If the MRLs are set for adults, then from the point of view of children the true safety limits - as yet unknown - may be greatly exceeded.
John Wargo warns that the risk may be especially high for children during three vulnerable growth periods in their lives when pesticides are most likely to cause cancers: in utero, infancy and prepuberty. In utero and in infancy the neurological system is rapidly forming, so that the risk of brain tumours or neurological damage is more likely. At the beginning of puberty, the reproductive organs such as breasts, ovaries and testicles are most vulnerable. All of these reproductive cancers are on the increase in this State.
John Wargo warns that the entire area of pesticides is so complex that the technology and the methodology to test whether they are truly safe do not exist.
We live with pesticides every day in our food and water. DDT - banned in the US and Europe for a generation - lingers in the environment. But so do the approved pesticides. There are more than 70,000 pesticide products registered for use in the world marketplace, controlled by 20 main companies whose business totals $25 billion.
In Europe, the World Health Organisation and EU set safe limits, often taking their lead from the US FDA. These limits are based on estimates of the average adult's consumption of pesticide residue containing foods. Thus the MRLs are set for the "average" diet of the "average" adult and cannot by definition also apply to children, who have smaller body mass but are also more susceptible to the effects of pesticides. In addition, children are more likely to eat large amounts of one particular food and if this contains high pesticide residues, they could be at risk of cancer.
Two thirds of all pesticides are used on three crops - cotton, corn and apples. Toddlers, for example, tend to drink vast quantities of apple juice. Yet apples are allowed to contain residues of up to 100 different pesticides. Pesticides concentrate during food processing, so that apple juice can contain far higher levels of pesticides than the apples used to make them.
The same is true of other processed fruit and vegetables. Even re heating food concentrates the pesticides in them and makes them riskier.
Children are also more susceptible than adults, especially from conception to the age of five, because they drink more fluids and are thus more likely to be harmed by pesticides in groundwater, if they live in agricultural areas. Bottle fed babies are especially at risk since not only may the water used to make their bottles be contaminated, but the soyabean oil used to make formula can contain pesticide residue.
The (Irish) Department of Agriculture's 1993 report gave a picture of the sort of pesticides which are found in our fruit and vegetables. One sample of satsumas contained residues of six pesticides. Three samples of parsnips and courgettes contained the dangerous, prohibited pesticide, dieldrin, proven to be carcinogenic. DDT - so dangerous that it was banned in the western world for 20 years was found in scallions from Mexico.
Of particular concern was the presence of chlorfenvinphos in some of the carrots tested, which amounted to 63 per cent of the adult average daily intake in one portion. In a batch of satsumas, it reached 76 per cent of the adult ADI. It is easy to see how the safe level for children could be exceeded by a child eating one satsuma.
Organophosphates, such as chlorfenvinphos, should especially concern us because children are more susceptible than adults to these chemicals' effects on the nervous system. Organophosphates - also found in some sheep in the Republic - have increasingly replaced organochlorine insecticides such as DDT and dieldrin after revelations of how devastating they can be.
Yet organophosphates are responsible for the majority of poisoning cases reported to the US Centers for Disease Control and the World Health Organisation. In 1989 alone, they caused 20,000 pesticide poisonings in the US. Organophosphates inhibit cholinesterase, thereby causing an accumulation of acetylcholine in the central nervous system leading to anxiety, restlessness, insomnia, headaches, emotional instability, nightmares, apathy and confusion.
JOHN Wargo claims that while organophosphates do not accumulate in the food chain or the human body, accumulation of the cholinesterase inhibiting effect can occur, leading to signs and symptoms of poisoning after small, repeated doses, either on the farm or in the diet.
Such a cumulative effect is never taken into account when "safety" limits are being proscribed, John Wargo argues.
In the Republic, we have focused recently on the need to enforce safety limits on foods. But what if those limits themselves are faulty?
Wargo believes that knowledge about pesticides risks must be taken away from the cloistered world of science and become international common property to which consumers have access. He also thinks that consumers should be forewarned of products containing pesticide residues - including food and drinking water.
He also says that governments, rather than balancing risks to human health against benefits in terms of agricultural productivity, must make the protection of human health paramount.
"The predominant standards for pesticides registration - risk benefit balancing - has been implemented in a way that permits humans to experience greater than trivial risks without their knowledge or consent," he writes. "These outcomes have been justified not only by claimed benefits, but also by employing risk averaging, which avoids considering highly exposed or susceptible groups such as children."
In what other areas of our lives are we exposed to greater than trivial risks without our knowledge? The time has surely come for consumers to stop relying on the nanny State and the agricultural chemical companies to protect them, and to wake up and demand answers. If the new Food Safety Board is serious about its business, it will start asking questions about fundamental pesticide safety, not just about managing the set limits.